make sure email from addresses don't exceed 320 characters (TNL-4264)

clean up and fix quality violations

since get_course can never return None, we can remove these lines

lms/djangoapps/bulk_email/tasks.py

@@ -216,11 +216,6 @@ def perform_delegate_email_batches(entry_id, course_id, task_input, action_name)
     # Fetch the course object.
     course = get_course(course_id)
 
-    if course is None:
-        msg = u"Task %s: course not found: %s"
-        log.error(msg, task_id, course_id)
-        raise ValueError(msg % (task_id, course_id))
-
     # Get arguments that will be passed to every subtask.
     to_option = email_obj.to_option
     global_email_context = _get_course_email_context(course)
@@ -403,11 +398,32 @@ def _get_source_address(course_id, course_title):
     # For the email address, get the course.  Then make sure that it can be used
     # in an email address, by substituting a '_' anywhere a non-(ascii, period, or dash)
     # character appears.
-    from_addr = u'"{0}" Course Staff <{1}-{2}>'.format(
-        course_title_no_quotes,
-        re.sub(r"[^\w.-]", '_', course_id.course),
-        settings.BULK_EMAIL_DEFAULT_FROM_EMAIL
-    )
+    course_name = re.sub(r"[^\w.-]", '_', course_id.course)
+
+    from_addr_format = u'"{course_title}" Course Staff <{course_name}-{from_email}>'
+
+    def format_address(course_title_no_quotes):
+        """
+        Partial function for formatting the from_addr. Since
+        `course_title_no_quotes` may be truncated to make sure the returned
+        string has fewer than 320 characters, we define this function to make
+        it easy to determine quickly what the max length is for
+        `course_title_no_quotes`.
+        """
+        return from_addr_format.format(
+            course_title=course_title_no_quotes,
+            course_name=course_name,
+            from_email=settings.BULK_EMAIL_DEFAULT_FROM_EMAIL,
+        )
+
+    from_addr = format_address(course_title_no_quotes)
+
+    # If it's longer than 320 characters, reformat, but with the course name
+    # rather than course title. Amazon SES's from address field appears to have a maximum
+    # length of 320.
+    if len(from_addr) >= 320:
+        from_addr = format_address(course_name)
+
     return from_addr
 
 

lms/djangoapps/bulk_email/tests/test_email.py

@@ -20,7 +20,8 @@ from instructor_task.subtasks import update_subtask_status
 from student.roles import CourseStaffRole
 from student.models import CourseEnrollment
 from student.tests.factories import CourseEnrollmentFactory, UserFactory
-from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
+from xmodule.modulestore import ModuleStoreEnum
+from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
 
 STAFF_COUNT = 3
@@ -44,44 +45,77 @@ class MockCourseEmailResult(object):
         return mock_update_subtask_status
 
 
-class EmailSendFromDashboardTestCase(ModuleStoreTestCase):
+class EmailSendFromDashboardTestCase(SharedModuleStoreTestCase):
     """
     Test that emails send correctly.
     """
 
-    @patch.dict(settings.FEATURES, {'ENABLE_INSTRUCTOR_EMAIL': True, 'REQUIRE_COURSE_EMAIL_AUTH': False})
-    def setUp(self):
-        super(EmailSendFromDashboardTestCase, self).setUp()
-        course_title = u"ẗëṡẗ title ｲ乇丂ｲ ﾶ乇丂丂ﾑg乇 ｷo尺 ﾑﾚﾚ тэѕт мэѕѕаБэ"
-        self.course = CourseFactory.create(display_name=course_title)
-
+    def create_staff_and_instructor(self):
+        """
+        Creates one instructor and several course staff for self.course. Assigns
+        them to self.instructor (single user) and self.staff (list of users),
+        respectively.
+        """
         self.instructor = InstructorFactory(course_key=self.course.id)
 
-        # Create staff
-        self.staff = [StaffFactory(course_key=self.course.id)
-                      for _ in xrange(STAFF_COUNT)]
+        self.staff = [
+            StaffFactory(course_key=self.course.id) for __ in xrange(STAFF_COUNT)
+        ]
 
-        # Create students
+    def create_students(self):
+        """
+        Creates users and enrolls them in self.course. Assigns these users to
+        self.students.
+        """
         self.students = [UserFactory() for _ in xrange(STUDENT_COUNT)]
         for student in self.students:
             CourseEnrollmentFactory.create(user=student, course_id=self.course.id)
 
-        # load initial content (since we don't run migrations as part of tests):
-        call_command("loaddata", "course_email_template.json")
-
-        self.client.login(username=self.instructor.username, password="test")
+    def login_as_user(self, user):
+        """
+        Log in self.client as user.
+        """
+        self.client.login(username=user.username, password="test")
 
-        # Pull up email view on instructor dashboard
-        self.url = reverse('instructor_dashboard', kwargs={'course_id': self.course.id.to_deprecated_string()})
+    @patch.dict(settings.FEATURES, {'ENABLE_INSTRUCTOR_EMAIL': True, 'REQUIRE_COURSE_EMAIL_AUTH': False})
+    def goto_instructor_dash_email_view(self):
+        """
+        Goes to the instructor dashboard to verify that the email section is
+        there.
+        """
+        url = reverse('instructor_dashboard', kwargs={'course_id': unicode(self.course.id)})
         # Response loads the whole instructor dashboard, so no need to explicitly
         # navigate to a particular email section
-        response = self.client.get(self.url)
+        response = self.client.get(url)
         email_section = '<div class="vert-left send-email" id="section-send-email">'
         # If this fails, it is likely because ENABLE_INSTRUCTOR_EMAIL is set to False
-        self.assertTrue(email_section in response.content)
-        self.send_mail_url = reverse('send_email', kwargs={'course_id': self.course.id.to_deprecated_string()})
+        self.assertIn(email_section, response.content)
+
+    @classmethod
+    def setUpClass(cls):
+        super(EmailSendFromDashboardTestCase, cls).setUpClass()
+        course_title = u"ẗëṡẗ title ｲ乇丂ｲ ﾶ乇丂丂ﾑg乇 ｷo尺 ﾑﾚﾚ тэѕт мэѕѕаБэ"
+        cls.course = CourseFactory.create(
+            display_name=course_title,
+            default_store=ModuleStoreEnum.Type.split
+        )
+
+    def setUp(self):
+        super(EmailSendFromDashboardTestCase, self).setUp()
+        self.create_staff_and_instructor()
+        self.create_students()
+
+        # load initial content (since we don't run migrations as part of tests):
+        call_command("loaddata", "course_email_template.json")
+
+        self.login_as_user(self.instructor)
+
+        self.goto_instructor_dash_email_view()
+        self.send_mail_url = reverse(
+            'send_email', kwargs={'course_id': unicode(self.course.id)}
+        )
         self.success_content = {
-            'course_id': self.course.id.to_deprecated_string(),
+            'course_id': unicode(self.course.id),
             'success': True,
         }
 
@@ -130,6 +164,13 @@ class TestEmailSendFromDashboardMockedHtmlToText(EmailSendFromDashboardTestCase)
         self.assertEqual(len(mail.outbox[0].to), 1)
         self.assertEquals(mail.outbox[0].to[0], self.instructor.email)
         self.assertEquals(mail.outbox[0].subject, 'test subject for myself')
+        self.assertEquals(
+            mail.outbox[0].from_email,
+            u'"{course_display_name}" Course Staff <{course_name}-no-reply@example.com>'.format(
+                course_display_name=self.course.display_name,
+                course_name=self.course.id.course
+            )
+        )
 
     def test_send_to_staff(self):
         """
@@ -268,6 +309,42 @@ class TestEmailSendFromDashboardMockedHtmlToText(EmailSendFromDashboardTestCase)
             [self.instructor.email] + [s.email for s in self.staff] + [s.email for s in self.students]
         )
 
+    def test_long_course_display_name(self):
+        """
+        This test tests that courses with exorbitantly large display names
+        can still send emails, since it appears that 320 appears to be the
+        character length limit of from emails for Amazon SES.
+        """
+        test_email = {
+            'action': 'Send email',
+            'send_to': 'myself',
+            'subject': 'test subject for self',
+            'message': 'test message for self'
+        }
+
+        # make very long display_name for course
+        long_name = u"x" * 321
+        course = CourseFactory.create(
+            display_name=long_name, number="bulk_email_course_name"
+        )
+        instructor = InstructorFactory(course_key=course.id)
+
+        self.login_as_user(instructor)
+        send_mail_url = reverse('send_email', kwargs={'course_id': unicode(course.id)})
+        response = self.client.post(send_mail_url, test_email)
+        self.assertTrue(json.loads(response.content)['success'])
+
+        self.assertEqual(len(mail.outbox), 1)
+        from_email = mail.outbox[0].from_email
+
+        self.assertEqual(
+            from_email,
+            u'"{course_name}" Course Staff <{course_name}-no-reply@example.com>'.format(
+                course_name=course.id.course
+            )
+        )
+        self.assertEqual(len(from_email), 83)
+
     @override_settings(BULK_EMAIL_EMAILS_PER_TASK=3)
     @patch('bulk_email.tasks.update_subtask_status')
     def test_chunked_queries_send_numerous_emails(self, email_mock):